For Nasdaq, it wasn’t exactly an unheard of event, though it was among the first times in recent memory the entire exchange stopped trading.

Back in 1994, the exchange suffered several embarrassing outages, the most memorable being a 34-minute power outage caused by a squirrel. That was, amazingly enough, the second time a furry rodent had closed the Nasdaq in a seven year period.

Here’s how WSJ covered the Aug., 2 1994 outage

Yesterday’s power outage, which United Illuminating Co.’s Trumbull office said was caused by a squirrel, brought screen-based Nasdaq trading to a halt beginning at 1:17 p.m. EDT, according to Nasdaq officials. When the Trumbull emergency power system failed to kick in immediately, Nasdaq officials scrambled to shift to its Rockville, Md., backup computer site. That switch took 34 minutes. Nasdaq officials said the last time the back-up power system was tested was July 4.

…

Yesterday’s trading halt marked the second time in nearly seven years that a squirrel appears to have done in the screen-based trading system. In a December 1987 incident, a high-wire squirrel triggered a power outage in Trumbull that led to a 40-minute trading interruption.

“We know it was a squirrel contact — they may have found the body,” said Lucille Caliendo, a spokeswoman for United Illuminating, of Hartford, Conn. “Our understanding is that Nasdaq never lost service, but that they may have experienced a dip,” when a local outage affecting 1,600 customers in nearby Shelton, Conn., occurred, she said.

Thankfully, the utility appeared to be taking it seriously at the time:

The utility spokeswoman said her company has been attempting to improve the squirrel-proofing of power lines in the heavily wooded area.

No squirrels have been found at the scene of Thursday’s incident, as far as MoneyBeat is aware.